समाजशास्त्रीय साहित्य में 'आभासी-समूह' (Quasi-group) शब्द का सर्वप्रथम प्रयोग किसने किया था?

Which of the following is considered the primary and basic social group in society?

A researcher is comparing the influence of family and student councils on learners' values. Which distinction between social groups is most relevant for understanding the nature of these influences?